Erecting device for gyroscopes



April 5, 1950 w. R. WEEMS ETAL 2,505,021

ERECTING DEVICE FOR GYROSCOPES Filed Oct. 1, 1945 4 Sheets-Sheet l I NVENTORS Mam/w e. 11 55/145 April 25, 1950 w. R. WIEEMS ET AL ERECTING DEVICE FOR GYROSCOPES 4 Sheets-Sheet 2 Filed Oct. 1, 1945 INVENTORS W/LL/FM E. WEf/VJ 505527' F. IVE/6W7 mmw April 5, 1950 w. R. WEEMS ET AL 2,505,021

ERECTING DEVICE FOR GYROSCQPES Filed Oct. 1, 1945 4 Sheets-Sheet 3 Lg INVENTORS MIN/7M E. WEE/W5 45637 19 l e/6147' BY fl-Jeu 4 April 25, 1950 w. R. WEEMS ETAL 5, ERECTING DEVICE FOR GYROSCOPES Filed Oct. 1, 1945 4 Sheets-Sheet 4 INVENTORS W/Ll/fi/H E. WEE/U5 be n r o ed vie va t vi when W t. h th .hendhlhm Ji ter ihe en the vin ree e w .ihevs i axle t eeee ehe en er eefl Patented Apr. 25, 1950 ERECIjING DEVICE noncmoscorns .nw e ehqb n .e-iweie iwpay i Q1310 I 7 Application October 1, 1945,:SerialN0. 6192278 ('Gnanted under the act of March 3, 1883, as

a neiiaea April 30,

Thei eht eh.ene hee ee d n iereeverhmehte leeie sesw th hi epe m h to us of any royalty'thereon.

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to d eetieh n; an le releeeee tee iab ish a erfi ee e eh el e e .h tee e aintain its axis 1 fixed in. .eh e .,andthemehihlv s en fh e main in the true vertical due to rotation giithe earth a d movement e the .eirh eh 1 e t v to h rthheeq d hely,

, e3 .Ieeeehh tl ei to e ,free s reeeq euehpthe heehihehl po nt to thecenter of the ear t or selhav e fetellv. emploxed, Pfin dulums which co ntr ol air jets or electrgmagnets to produce tor ues on thellgyljogiqr ceusing erection of the same; b

We are aware that for ,inany years it has b n wn. th me .r ended Pe eh s i nin top assistssincausi n er tion of the top due to the h hi I et eh see fehvhed TGvrem by Ee r Wehh wyil lev h r eh r uhhe 193 rpp-fZ- ehs 7? ert1e e @e .ah 4 flll f i fi iil 7,. he1 iveN MAM-Q A- e rt N 1 19 2- So far a we howev r i has never been proposed to utilize this very simple and eirective principle in conjunction with e a i e ieehed eeh halhlh .3 eue r e e e ae lie es he- In ee erdehe it eee e th e e en ihvehtieh he reeeehe i meiintedzin e mhel an t {Spin i l wi ehrre idedweh ts l we en with e em eh iee heednh e n a e .afri

h n e eerh .Je-v flhehdhl h h vete lv suppor o h v eithe one deg ees o ..f eed m- R tati n Q th ehihaxle eu e iee b tw n th hemis h hee e e th uhe e h t r t ese Ade a ieui e e ep hhe e ME e eh .fd Yie a,

say to lfi lum having a friction element in engagement with an element driven by the gyrorotor such -thatthe friction forcepro dnces atorque onthe gyroscope causing precession of the gyrpscope :ina-direction such' as to bring the spin agisfof 20 the gyroscope into coincidence with a vertical --deterrnined by the pendulum.

Other objects and features of the invention -wi 1l-appear by-reference to the detailed description hereinafter given, taken in conjunction with the appended drawings, in which! "Fig. *1 is a diagrammatic view in front elevationillustratingthe principles of the invention;

Figuz-is aview of the structure of Fig. 1, in

. side elevation;

Fig.8 is atop plan view of a gyroscopic control device incgrporating the principles of the invention;

'JFigfi is a view-partly in sectiqn taken cnline Fig' 5; is'a view partly-in section taken on line 5-5 of Fig. $3 and 'Fig. 6 is a schematic wiring diagram pi -the device of Fig. ;3 showing the erection cut-out switch operated by a rate-ofeturn gyroscope.

The basic features of the invention will be understood by reference to Figs. 1 and 2 of-the drawings. Asseen in these flgures the reifer- 1. 5 6 hum n i ate evreeee erete 9 t5 h h hr h'dh eii tim hev h hi sez e 3 ad pted fi heu hehht'eslintestine the elmhe rih lxhehht h 9 29 ehe r t 't s in aelesh- .wieedheetiee. e -e ehxhtqm beve b an able zhe hew h q x eit te L ass m d evh gimbal suspended to have threedegnees oi j reeden 9? ret iiehe 4. enelemeet his .xigldlmemre .testh rlen vpe the nexlelehd i eehetrhe e shriee nih th teem v9 element 3 rotates continuously with the rotor I and frictionally engages a spring loaded plunger 4 suitably faced with friction material such as leather and mounted for vertical movement in a base 5. The spring loading of the plunger 4 need only be very light. The base 5 is supported on a transverse member 6 on which pen dulum weights 1 are secured, the member 6 and weights I being supported for fore and aft oscillation about axis a a by arms 8 pivotally supported as at 9 from a gimbal ring if) which in turn is supported for rotation about axis 17-12 by pivots II. It is thus seen that the pendulum is universally mounted for movement about the intersection of the axes H and b-b, which intersection is coincident with the center of gravity G of the rotor system.

If it is assumed that the rotor I is rotating in the direction as indicated by the arrow and the -.rotor is laterally tilted such that the spin axis is inclined from the pendulum vertical as indicated by the angle theta (0), Fig. 1, an unbalanced friction force will occur at the point of engagement between elements 3 and G. This friction force will tend to move the pendulum weights back as seen in Fig. l producing a contrary revaction as indicated by arrow F, Fig. 2, on the friction element 3. This reaction force F and tion of the gyrorotor, is slow so that the erecting its moment about point G may be replaced by an equal force F1 acting in the plane of the center of gravity G of the rotor and a couple comprising forces F2, times the lever arm C equal respectively to the force F and. the lever arm of F about the center of gravity of the rotor. The

moment F2.C of the couple due to friction will produce a clockwise toroue as seen in Fig. 2 on the gyrorotcr l which would tend to produce an angular acceleration of the rotor about axis a a, Fig. 1.

When a gyroscope rotor is spinning and is acted upon by an external torque normal to the spin axis the spin axle will precess about a third axis normal to the spin and torque axes in such a direction that if continued the pin axis would lie in the axis of the applied. torque with the direction of spin in the same direction as the sense of the applied torque. In order to satisfy this general rule with the gyrorotor l of Fi l rotating in a clockwise sense as seen from above and an external torque due to the friction erecting device acting in a clockwise sense about axis aa when viewed from right to left, the spin axle must rotate in a clockwise sense about axis bb looking from front to back in order to lie in the torque axis with the direction of spin in the direction of the applied torque. It will thus be apparent that the gyrorotor I will precess such that the angle theta is diminished and the spin axis will become coincident with the pendulum vertical. When the spin axis and pendulum vertical are coincident the friction between plunger 4 and friction element 3 produces a torque resisting the rotation of the rotor I but produces no torque normal to the spin axis of the rotor. It will be noted that theoretically the friction force between the elements 3 and 4 will be dewill be reversed in sign causing a corresponding ,reversal in the direction of precession and again causing erection of the gyro spin axle into codevice is suitable for use in conjunction with a gyro employed for example in a flight indicator.

A practical embodiment of the invention in a gyroscopic device suitable for use as an automatic pilot for aircraft is illustrated in Figs. 3 to 5. inclusive.

Referring to these figures, reference numeral 20 indicates a rectangular base provided with vertical uprights 2i longitudinally spaced and each provided with a bearing 23 (see Fig. 4) which bearings serve to journal trunnion pins 24 of an outer gimbal ring 25. The axis of the trunnion pins 2% are, for example, aligned with the longitudinalor rolling axis of an aircraft when the device is employed for automatic control purposes.

The outer girnbal ring 25 is provided with a pair of ball-type trunnion bearings 26 (note Fig. 5), which serve to journal trunnion pins 2'! which lie in an axis at right angles to the axis of trunnion pins 2G and in turn are rigidly secured to an inner gimbal ring 30 which is provided with a boss 33 counterbored as at 34 to serve as a mounting for a conventional direct current electric motor 35, the latter being secured in the imbal frame by means of clamping screws (not shown).

The gimbal'ring 30 is bored as at 35 (see Fig. 5) to receive a bearing 31 for the armature shaft 38 of the motor 35 and a fly-wheel or gyrorotor 49 is secured to the shaft 38 to be driven thereby, the rotor being positioned within the gimbal ring 30. The shaft 38 extends through the bearing 37 and at its lower end has a hemispherical head 42 secured thereto for rotation by the motor 35 in unison with the rotor 43. The hemispherical head 42 is preferably made such that its geometrical centercoincides with the intersection of the gimbal axis and the inner gimbal ring and motor assembly are so balanced that the center of gravity of the gyro system lies on the intersection oi the gimbal axis, and hence the gyroscope is non-pendulous. The head 42 corresponds to the similar element 3 of the device of Figs. 1 and 2 and cooperates with a plunger 45 faced with friction material, as indicated at 46, which engages the smooth outer surface of the head 32. Plunger 45 is provided with a stem portion 4? which is reciprocably guided in a base 49 and urged upward by a biasing spring 48. The base 49 also supports electromagnets 50, the pole pieces 5! of which underlie an iron armature 52 secured to the stem l? such that when the electromagnet coil 50 are energized, the armature 52 is pulled downward ,against the resistance of spring 48 andcauses disengagement between the friction facing of the plunger with the friction head 42. The plunger 45 corresponds to the friction element i. of Figs. land 2 and functions in a similar manneras an erecting mechanism in cooperation with thefriction head 42 in a manner as explained with respect ,to the schematic device of Figs. 1 and 2. Theelectromagnets provide a means for rendering the erecting mechanism inoperative atI-Will so .that when the friction p er 45 is retracted thegyroscopic system is that of a free gyro'and under such conditions,

creamer except 'forfriction,the"axispfz'slraftiidwouhi Pemainfixe'd'inspace.

The base 4.9 and electromagnetsififl' areisecured tofla transverse channel member 55 "which has pendulum weights 5'6 securedito -theumderside thereof. The channel memberif)EiSTsecured'at-its en'ds'to armsil, one ofwhichyasseeninl 'igffi, isjoffinsulating material. .Eachdf'the arms is provided with an antifrictionbearin g 58*topro- Vidfejiormovementof the pendulousweightsin .a fore and aft plane aboutpivotipinsf59-wh'ich'are secure'd'to a gimbal ring 60 which is,"in*turn, proiii'ded withitwo antifriction bearingswimounted onrextensions of .theLtrunriionbinsfl so'thatthe pendulum wights'ii'fi areTree,toimovelaterally;

Mounting plates 6.2 and ;provided"with in sulating supports .64 and Z65, respectively .are positioned onthe respective ;gimba1 rings'25 and 130 such that movement or an aircraft in 'roll or pitch can, through electrical ,or pneumatic pickoff means (not shown) -actuate servomechanism .to (function asan automatic ,pilottin azmann'er well known'in the :art.

The current .is supplied .Tior operation of the electricmotoffllandffor'the operationof electromagnets 5.0 from a connector plug 110 ;(Figs. '3 and I4) Whichiisiadapted tolbe connected"to a source-of direct,cllrrezit;p.otential (not shown). Current ,is ".ledlfrom ,plug by means of, a conductor 11 l .-and1brush"12 1iJO=QOIitaGtblittDn13 and conductor ,14 to racontact spr'ingl'fi which engages .a contactlbuttoni'lfiiposltionedron thaendo'f .one oftheitrunnionrpins L271 or" thegimbalcringiafl and connected. to an insulated conductonpositioned withincthe trunnion pin and serving .to conduct current =,to the irnotor L rfor .operation thereof. .Thereturn -ci-rcuitoside of .the, motor (is grounded to ,the gimbal ringl30,- which .ground is completed .tolthe batterycthrough:suitablecontact springs such that lrotationro'f the .gimbal rings will .not produce variation inresis'tanceiin the motor circuit.

Curren-t -.is also led..from tplugl connection 10 to .a'switchLl-flalEigsnti and 4) .andr-througha contact spring "ll tozarcon-tact spring J8rmounted on vthe,pemiulurn suppor-tifongimbal Q60 :from which current is led by means of a conductor :19 ,and brush -.-flil,.-springrringv8leand conductor 82 to the seriesrconnected electnornagnet coils 50, ground return 83 serving to connect the other side of the e1ectromagnetsitozthelbattenynircuit through ,the grounded gimbal rings andirame.

The device illustrated in Figs iicto 5,vinclusive, operates in a manner identical'to that described with reference to-Figs. l'and Zin'that when the assembly is placed in aniaircraft and the unotor i5. energized, the gyroscope .:rotor 40 will Ibegin lto turn and after attaining ea crrormal .sneedso'i roperationyiill tend. to .maintainithe planecof the spin .axle 38lfixedinsnace. "The erecting'head ,"42,however, rotates .with .thexrotor 40, and 'ifthe spin axis is not coincidental with the average true vertical as determined by the pendulum, erecting forces will be produced by the interaction of the friction existing betweenthe head "42 and plunger 45 to causethegyroscqpeto be erected until the sping axis coincidesviithfithe axis of plunger 45; Tihis-actionwvill take place irrespective of whether the pendulum is displaced along one or both axes and so long as the friction facing 45 of the plunger 45 remains in contact with the friction erecting head 42. erecting forces will be produced Whenever there is lack of coincidence between the spin axis and the apparent vertical as determined by the pendulum.

6 Wl'ierethe device ism-ountedon-amaircraftrthe pendulum will be subject, during :turns, to =aceelerating forces causing the pendulum to r move out of the true vertical. Under suchconditions it may be undesirable ii toerect the gyro intozthe plane of the apparent vertical and during such periods-as the pendulum is subjected toacceleration forces, the erecting mechanism -may -be disabled by"closing-swi.tch Illa which willenergize the electromagnets 50 to cause: plunger 45 to be retracted," leaving th-e gyroscopic' system operating as=a free gyro. The switch 'lfiwmayb'e operated manually orby means of a radio signal actuated remotecor'itrol system -'or it may be operated by a rate-ofturn gyroscope in a manner *asillustrated iir Fig; '6.

seeninFig-"S; battery 96, having one terminal ther-co r grounded by means of conductor '9 l supplies currentto "a conductor 92 and motor (rdthe-return-side 9315f which is grounded to complete the circuit to the battery. Currentis also supplied by means of a branch conductor 9'4"to a spring contact '95 associated with ;a'"rate-ofturn gyroscope, generallyindicated bythe reference numeral Hit. The turn gyroscope 'or -=turn indicator of conventional design is provided with trunnions l iii adapted "to pivotally support a ginibal ring 162 for rotation' about ==a fore and a'ft axis,lthe giniba'l ring serving "as a support for a conventional-electrically driven gyroscope which is supplied with current "from brus'h deand has its return'circuit grounded to-complete the circuitto battery 93. 'The' gimbal ring 102 is provided with an "arm 4M biased by =springs 1% "to -'a normal *central --position but "rotation of the assemblyin azimuth will-cause precession of the gyroscope 493 -to 'cause rocking of the gimbal ring Hi2 abouttrunnions 1'01 ,"whi'ch-rocking movement is resisted by one of the springslufi which will deflect 'such that rotation of arm' "Hi4 will be: proportionalto the precession torque which-is in'turma function of the r-ate-of-turn ofitheassembly. Arm '1 M isprovided-atitslower end "with a contact-"Lilli which is adapted, upon displacement from -the neutral position, to tengage "either o'fa pair of adjustable -contacts I01 whichare electrically connectedby means" of T0011? ductor M8 to the electromagnet :cdils "50, 'a 'return circuit being providedby means of 'con'ductor i 09. "Currentfrom'brushiib'is carriedthrough the 'irame I132 'to contact Hi5 such that if the aircraft upon which the assembly is mounted turns at greaterthan the predetermined rate determined by the adjustment of contacts [101, the electromagnetsfill willbe ener gized, causing retraction ofplunger 14.5 out of (engagement with "friction erecting head 62 to .leave the spin axis of the gyrorotor Ml fixed in space until ltherate- ,of-turn of the aircraft decreases ,to..the .prede terrn'ine'd ,value.

-While .the invention has .beenrillustrated .and ldescrihedlasutilizing a universally mounted ipen- .dulum, it .is obvious .that the pendulum :may be fixed lforlmovernentrabout a single 'axis, Lin-which case the gyroscope will belerected so thatiits :spin 'EfiXi-S willlie in.the -plane of;the.true-,vertical but may be.inclined theretorin-a plane at-rightnngles to the plane'of movement of the pendulum. The spin axle will be erected with respect to the center line of the pendulum plunger. This type of construction would be employed where the gyroscope is sensitive only to pitch or roll but not both.

While the invention has been described as applicable to gyroscopic control systems such as employed in automatic pilots, it is obvious that the erecting mechanism can be employed in flight indicators known as gyro horizons in which the gyroscope rotor is used to determine a reference plane for indicating, through suitable indicating mechanism, the attitude of the aircraft.

It should be further understood that it is not essential that the friction element 42, Figs. 3, 4 and 5, be mounted directly on the rotor shaft but the same may be driven by means of reduction gearing so as to rotate at a considerably slower speed than the rotor. In such a case, however, it is still essential that the friction head 42 rotate in the same direction as the rotor shaft and be mounted concentrically therewith.

While one form of the invention has been illustrated and described, it will be apparent to those skilled in the art that various modifications may be made therein which will come Within the scope of the invention as defined in the appended claims.

We claim: 1 1. In a gyroscope device, a rotor, a spin axle supporting the rotor, gimbal means for rotatably supporting the rotor spin axle for three degrees of freedom, a pendulum member pivotally carried for movement about one of the three axes of freedom of the rotor spin axle, relatively rotatable friction elements mounted respectively on the pendulum member and the rotor spin axle for engagement with each other to precess the rotor spin axle into the pendulum vertical position, resilient means normally maintaining said friction elements in frictional engagement with each other and means responsive to accelerations tending to swing the pendulum member out of vertical for moving one of said friction elements out of frictional contact with the other frictional contact element.

2. In a gyroscope device, a spin axle, a rotor mounted on said spin axle, at least one gimbal ring for supporting the rotor spin axle for rotative freedom about an axis normal to the rotary axis of the spin axle, a gravity controlled pendulum member supported to define an average true vertical at least in the plane normal to said axis of rotative freedom, a pair of relatively rotatable friction elements movable to and from frictional engagement with each other, one of said friction elements being mounted on and rotatable with the rotor spin axle and the other friction element being constructed and arranged such that the tilt of the spin axle relative to the pendulum vertical,

'When the friction elements are in engagement with each other, produces a torque on the rotor spin axle causing the rotor to precess the rotor spin axle into coincidence with the pendulum vertical, resilient means normally holding the friction elements in frictional engagement with each other, electromagnetic means energizable to move one of said friction elements out of frictional engagement with the other friction element, and acceleration responsive means for energizing said electromagnetic means when the rate of acceleration exceeds a predetermined rate to disengage the friction elements.

3. In a gyroscope for establishing a horizontal reference line, a p'owerdriven rotor element having a vertical spin axle, a gimbal ring pivotally supported for rotation about at least one horizontal axis, bearing means in the gimbal ring for journalling said spin axle for rotation, and said spin axle extending downwardly below said gimbal ring, a head in the form of a spherical segment concentrically mounted on the extended portion of said spin axle, a gravity controlled pendulum for establishing an average vertical, a spring loaded normally engaging retractable plunger carried by said pendulum frictionally engaging said head, an electromagnet mounted on said pendulum for retracting the plunger, and rate of turn responsive means for energizing said electromagnet to disengage the plunger from the head during turns.

4. In a gyroscope device for establishing a horizontal reference line, a power driven rotor element having a vertically disposed spin axle, a gimbal ring pivotally carried for rotation about at least one horizontal axis, bearing means in said gimbal ring for rotatively journalling said spin axle, said spin axle extending downwardly below said gimbal ring, a head in the form of a spherical segment concentrically mounted on the extended portion of the spin axle, a gravity controlled pendulum for establishing an average true vertical, a spring loaded retractable plunger carried by the pendulum normally in frictional contact with the rotative center of the spherical surface of the head When the spin axle and the pendulum are vertical, electrically controlled disengaging means for disengaging the plunger from the spherical surface of said head including a normally open energizing circuit, a rate of turn gyroscope having a spin axis tiltable incident to turning movements in excess of a predetermined rate of an aircraft on which the gyroscope device is mounted, and circuit closing means operable by a predetermined degree of tilt of said rate of turn gyroscope spin axis for closing said energizing circuit to disengage said plunger from the spherical head during said tilting movements in excess of said predetermined degree of tilt of the rate of turn gyroscope spin axis to automatically interrupt the erection of the rotor spin axis during said tilting of the rate of turn gyroscope spin axis.

WILLIAM R. WEEMS. ROBERT A. WRIGHT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,825,345 Fieux Sept. 29, 1931 2,267,411 McNairy Dec. 23, 1941 2,339,606 Sias Jan. 18, 1944 2,422,120 Noble June 10, 1947 2,428,925 Borell Oct. 14, 1947 FOREIGN PATENTS Number Country Date 849,190 France Aug. 7, 1939 141,477 Great Britain Apr. 22, 1920 r 166,800 Great Britain July 28, 1921 291,047 Great Britain Mar. 19, 1928 

